Sexual behaviour, sexually transmitted infections and attitudes to chlamydia testing among a unique national sample of young Australians: baseline data from a randomised controlled trial.

BACKGROUND: Chlamydia infection is the most common notifiable sexually transmitted infection (STI) in Australia and mostly affects young people (15 - 25 years). This paper presents baseline data from a randomised controlled trial that aimed to increase chlamydia testing among sexually active young people. The objectives were to identify associations between sexual behaviour, substance use and STI history and explore attitudes to chlamydia testing. METHODS: This study was conducted in cyberspace. Study recruitment, allocation, delivery of interventions and baseline and follow up data collection all took place online. Participants were 16 - 25 years old and resided in Australia. Substance use correlates of sexual activity; predictors of history of STIs; barriers to and facilitators of chlamydia testing were analysed. RESULTS: Of 856 participants (79.1% female), 704 had experienced penetrative intercourse. Sexually active participants were more likely to smoke regularly or daily, to drink alcohol, or to have binge drunk or used marijuana or other illicit substances recently. Risk factors for having a history of any STI were 3 or more sexual partners ever, 6 or more partners in the past 12 months, condom non-use and being 20 years or older. Almost all sexually active participants said that they would have a chlamydia test if their doctor recommended it. CONCLUSIONS: Sexually active young people are at risk of STIs and may engage in substance use risk behaviours. Where one health risk behaviour is identified, it is important to seek information about others. Chlamydia testing can be facilitated by doctors and nurses recommending it. Primary care providers have a useful role in chlamydia control. TRIAL REGISTRATION: Australian and New Zealand Trials Registry ACTRN12607000582459.

Early cystic fibrosis lung disease detected by bronchoalveolar lavage and lung clearance index.

RATIONALE: Unrecognized airway infection and inflammation in young children with cystic fibrosis (CF) may lead to irreversible lung disease; therefore early detection and treatment is highly desirable. OBJECTIVES: To determine whether the lung clearance index (LCI) is a sensitive and repeatable noninvasive measure of airway infection and inflammation in newborn-screened children with CF. METHODS: Forty-seven well children with CF (mean age, 1.55 yr) and 25 healthy children (mean age, 1.26 yr) underwent multiple-breath washout testing. LCI within and between-test variability was assessed. Children with CF also had surveillance bronchoalveolar lavage performed. MEASUREMENTS AND MAIN RESULTS: The mean (SD) LCI in healthy children was 6.45 (0.49). The LCI was higher in children with CF (7.21 [0.81]; P < 0.001). The upper limit of normal for the LCI was 7.41. Fifteen (32%) children with CF had an elevated LCI. LCI measurements were repeatable and reproducible. Airway infection was present in 17 (36%) children with CF, including 7 (15%) with Pseudomonas aeruginosa. Polymicrobial growth was associated with worse inflammation. The LCI was higher in children with Pseudomonas (7.92 [1.16]) than in children without Pseudomonas (7.02 [0.56]) (P = 0.038). The LCI correlated with bronchoalveolar lavage IL-8 (R(2) = 0.20, P = 0.004) and neutrophil count (R(2) = 0.21, P = 0.001). An LCI below the upper limit of normality had a high negative predictive value (93%) in excluding Pseudomonas. CONCLUSIONS: The LCI is elevated early in CF, especially in the presence of Pseudomonas and airway inflammation. The LCI is a feasible, repeatable, and sensitive noninvasive marker of lung disease in young children with CF.

Facilitating chlamydia testing among young people: a randomised controlled trial in cyberspace.

OBJECTIVES: Chlamydia notifications have been rising in Australia for over a decade and are highest in young people. This study aimed to evaluate the impact of an internet-based intervention on chlamydia testing among young people 16-25 years. METHODS: In this randomised controlled trial, recruitment, data collection, study interventions and follow-up occurred entirely in cyberspace, facilitated by a website. Eligible participants were aged 16-25 years and resided in Australia. The intervention group received personalised emails inviting interaction about chlamydia testing, while the control group received regular impersonal emails. Primary outcome was self-reported chlamydia testing at 6-month follow-up; secondary outcomes were condom use and changes in knowledge and attitudes. RESULTS: 704 young people completed baseline information, 40 were excluded and five withdrew prior to follow-up. The follow-up rate was 47.3% overall. In the intervention group, 40.6% (95% CI 30.7% to 51.1%) reported having had a chlamydia test at follow-up compared with 31.0% (95% CI 24.8% to 37.2%) in the control group (p=0.07). A per-protocol analysis found that those who engaged in email interaction were more likely to report chlamydia test uptake compared with those in the control group (52.5%, 95% CI 39.3 to 65.4% cf 31.0%, 95% CI 24.8% to 37.2%, p=0.002). There were no differences in secondary outcomes between groups. CONCLUSIONS: This is the first randomised controlled trial undertaken in cyberspace to promote chlamydia testing. E-technology may be useful in promoting chlamydia testing and healthcare seeking behaviour in young people.

Longitudinal analysis of resting energy expenditure in patients with cystic fibrosis.

OBJECTIVE: To assess whether elevated resting energy expenditure (REE) in female patients with cystic fibrosis (CF) persists longitudinally during late childhood and puberty. STUDY DESIGN: REE and body composition were measured 3 times in 2 years in 86 children with CF. Pubertal status, bacterial colonization, liver disease, pancreatic and pulmonary function, and genotype were determined, and linear mixed model analyses were used to determine predictors and changes in REE longitudinally. RESULTS: REE did not change with time allowing for fat free mass, pancreatic insufficiency (PI), or severe mutations. Pulmonary function and liver disease were not significant predictors of REE. Percentage predicted REE compared with control data was higher (P = .002) in female patients with CF (109.5%) and lower in male patients with CF (104%) and persisted with time. In post-menarchal female patients with CF, REE adjusted for fat free mass was 366 kJ/d lower than in pre-menarchal female patients, but still 112% predicted. CONCLUSIONS: This longitudinal study demonstrates that REE is elevated in patients with CF with PI and severe mutations. The elevation of percentage predicted REE was greater in female patients than male patients and persisted for 2 years, and during pubertal maturation, independent of pulmonary and liver disease. These results highlight the need for a high-energy diet throughout childhood and adolescence, particularly in female patients with PI.

Relation between hormones and body composition, including bone, in prepubertal children.

BACKGROUND: Sex differences in body composition exist before puberty, but the reason for this phenomenon is unknown. The physical changes that occur during puberty are mediated, in part, through sex steroids, insulin-like growth factor I (IGF-I), and leptin. However, data are lacking that address the extent to which concentrations of these hormones influence body composition, bone mass, and density in prepubertal children. OBJECTIVE: We investigated the effects of IGF-I, dehydroepiandrosterone sulfate, and sex steroids on body composition and fat distribution and the effects of these hormones and leptin on total body bone mineral content (TBMC) and volumetric bone mineral density (vBMD) at the femoral neck and lumbar spine (LS) in 255 healthy children (137 girls), aged 7-8 y. DESIGN: Body composition, fat distribution, TBMC, and vBMD were derived by using dual-energy X-ray absorptiometry. Association between variables was examined by using regression analysis. RESULTS: No sex differences were found in age, height, or weight. However, girls had significantly more total body fat, trunk fat, and higher LS vBMD but significantly less fat-free soft tissue, TBMC, and femoral neck vBMD than did boys. Girls also had significantly (P < 0.001) higher IGF-I, estradiol, testosterone, and leptin concentrations than did boys. Estradiol concentrations predicted percentage body fat, which supported an effect of estrogen on fat storage. Leptin had an independent effect on LS vBMD, which suggests a positive effect for leptin on trabecular bone. CONCLUSIONS: The hormones examined explained 3-17% of the variations in body-composition measures, fat distribution, and bone density, which suggests that other factors are important predictors of prepubertal sexual dimorphism.